It can be done and Ive done it but the glass and frame plays a roll as well as placement of the dish. I did one in a third floor loft / storage area in one of them old small town main street style buildings. The windows were about 100 years old if a day and with them closed it killed the signal down to %60, with them open it was at %95 so the glass and its frame played a role in the signal degridation.